/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: StartsWithCall.java,v 1.2.4.1 2005/09/05 09:05:28 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import java.util.Vector;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */
final class StartsWithCall extends FunctionCall {

  private Expression _base = null;
  private Expression _token = null;

  /**
   * Create a starts-with() call - two arguments, both strings
   */
  public StartsWithCall(QName fname, Vector arguments) {
    super(fname, arguments);
  }

  /**
   * Type check the two parameters for this function
   */
  public Type typeCheck(SymbolTable stable) throws TypeCheckError {

    // Check that the function was passed exactly two arguments
    if (argumentCount() != 2) {
      ErrorMsg err = new ErrorMsg(ErrorMsg.ILLEGAL_ARG_ERR,
          getName(), this);
      throw new TypeCheckError(err);
    }

    // The first argument must be a String, or cast to a String
    _base = argument(0);
    Type baseType = _base.typeCheck(stable);
    if (baseType != Type.String) {
      _base = new CastExpr(_base, Type.String);
    }

    // The second argument must also be a String, or cast to a String
    _token = argument(1);
    Type tokenType = _token.typeCheck(stable);
    if (tokenType != Type.String) {
      _token = new CastExpr(_token, Type.String);
    }

    return _type = Type.Boolean;
  }

  /**
   * Compile the expression - leave boolean expression on stack
   */
  public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    _base.translate(classGen, methodGen);
    _token.translate(classGen, methodGen);
    il.append(new INVOKEVIRTUAL(cpg.addMethodref(STRING_CLASS,
        "startsWith",
        "(" + STRING_SIG + ")Z")));
  }
}
